Sewing machine



Jan. 18, 1955 w, A, AYREs 2,699,745 SEWING MACHINE Filed D60. 12, r1951 INVENTUA WQLaMARAAy/Pss United States Patents@ SEWINGJ MACHINE Waldemar A. Ayres, Lakewood, Ohio, assignor to White Sewing,- Machiner Corporation, Cleveland,-=;0hio, a corporation of Delaware Application December 12, 1951, Serial-No. 261,185

4 Claimsr (Cl. 1122*-218):

This invention relates to a sewing machine and more particularly to an improved and novel arrangement for dynamically balancing the needle bar and the actuating mechanism therefor.

One of the limitations to the operating speeds of a sewing machine is the objectionable vibrations set up by a moving part, such as the reciprocating needle bar, operating at high speeds. The magnitude of the vibrations limits the operating speeds of the sewing machine and necessitates the use of slower operating speeds to maintain the vibrations at a minimum and to lessen the operating noises present in the machine.

The broad object of the invention is to provide a dynamically balanced needle bar mechanism in a sewing machine.

Another object is to provide in a sewing machine an improved and novel arrangement for dynamically balancing the needle bar and operating mechanism therefor which substantially eliminates vibrations in the sewing machine head occasioned by the reciprocation of the needle bar, even though the machine is operating at high speeds and thus produces a quieter and more efficient sewing machine.

Another object is to provide in a sewing machine an arrangement, such as defined in the previous objects, and which is simple, compact and does not substantially increase the size of the sewing machine head.

Further and additional objects and advantages not hereinbefore referred to will become apparent hereinafter during the detailed description of an embodiment of the invention which is to follow and which embodiment is illustrated in the accompanying drawing wherein,

Fig. 1 is a view, partially in front elevation and partially in section, of a sewing machine head equipped with a needle bar and operating mechanism therefor embodying the invention; the sectional portion of the head disclosing the construction of the needle bar and its operating mechanism with the needle bar being shown as in the lowermost point of its vertical reciprocating movement. i

Fig. 2 is a fragmentary view similar to the left hand portion of Fig. l but showing the needle bar at the uppermost point of its vertical reciprocating movement.

Fig. 3 is a transverse sectional view taken substantially on irregular line 3-3 of Fig. l looking in the direction of the arrows, and

Fig. 4 is a fragmentary partial end elevation and partial section of the sewing machine head, the end elevation and the section being taken looking from or on line 4 4 of Fig. 2 as indicated by the arrows.

The sewing machine head shown in the drawing and embodying the invention comprises a bed which supports the hollow bracket arm or gooseneck having a f vertical member or standard 11 and a horizontal member 12 on the free end of which is that portion generally designated as the face and indicated at 13.

It will be understood that the hook and feed mechanisms and the shafts for operating the same are carried by the bed 10 as is conventional and that said shafts are operatively connected to the main shaft 14 that is rotatably mounted in suitable bearings in the horizontal member 12 of the gooseneck as will also be well understood in the art. Any suitable power means for operating`the sewing machine can be employed and is not shown herein since it will be well understood.

The face 13 at the free end of the horizontal member 12 of the gooseneck mounts the usual presser foot 2,699,745 Ptented Jan. 18, 1955 15 whichneed'notibeireferredfto further herein: The main shaft `14` to the lleft `:of its bearing 16 haswsecuredf thereto a Ldisk 17 which 'carries aneccentric pin `18; A'on' its lefthandside ascviewed inFigs. H1 and 2. The needle the Scotch yoke 20.

The needle bar-.19\is provided on one side`th`ereof` and" for a portion of its lengthlwith` gear teeth. forming ca racki 21,-a vportion offwhichis alwaysflocatedsimarecessedf opening 22 formed internally'in'the-face'portion-13.1v An' idler gear 23 is mounted within the face portion 13 of the headstock on a horizontal pin or stub shaft 24 secured in the face portion and said idler gear 23 extends into the recess 22 and constantly meshes with the rack 21 on the needle bar 19. The face portion 13 of the gooseneck is provided internally with a cylindrical chamber 25 in which slides a counterweight or counterbalancing plunger 26 provided with gear teeth forming a rack 27, a portion of which is always located in a recess or opening 28 formed internally of the gooseneck and into which the idler gear 23 extends so as to customarily mesh with the rack 27.

The counterbalancing plunger 26 has secured thereto a guiding element 29 which may take any desired form but is shown as a headed screw secured to the plunger 26. The element 29 extends into a vertically extending slot 30 formed interiorly of the face portion 13 of the gooseneck, wherefore the plunger 26 is held against rotating movement in the chamber 25 while being free for vertical reciprocating movement therein.

lt will be seen that the chamber 25 extends vertically parallel to the needle bar 19 and that the plunger or member 26 is mounted in the chamber so as to reciprocate therein in out of phase relationship to the reciprocation of the needle bar 19 and that the movement of the needle bar is transmitted to the plunger 26 through the idler gear 24 which meshes with the rack 21 on the needle bar and the rack 27 on the plunger 26. The needle bar 19 and the member 26 are located in the vertical plane which passes axially through the main shaft 14.

The mass of the plunger 26 is predetermined in relation to the mass of the needle bar 19 and its operating mechanism so that its out of phase reciprocation with vrespect to the reciprocation of the needle bar functions to dynamically balance the latter and thus to reduce to a minimum vibrations in the gooseneck occasioned by the reciprocating needle bar. Consequently the operation of the needle bar even at high speeds will not create extreme vibration in the gooseneck and will result in quieter operation and greater eiciency of the sewing machine.

Although a preferred embodiment of the invention has been illustrated and described herein it will be understood the invention is susceptible of various modifications and adaptations within the scope of the appended claims.

Having thus described my invention, I claim:

1. In a sewing machine head having a reciprocating needle bar and mechanism for reciprocating said bar, means for dynamically balancing the reciprocating needle bar to minimize vibration in the sewing machine head and comprising guide means formed in said head and parallel to said needle bar, a member mounted in said guide means for reciprocation therein and correlated in mass to said needle bar, and means operatively interconnecting said bar and member to reciprocate the latter simultaneously with the bar but out of phase therewith and including rack teeth formed on the adjacent sides of said bar and member, and an idler gear mounted in said head intermediate said bar and member and meshing with said rack teeth.

2. In a sewing machine head having a main shaft rotatably mounted in the horizontal arm of the head and extending into the face portion at the free end of said arm, said shaft having secured to it within said face portion a disk provided with an eccentric pin, said face portion being provided with a vertically extending bore, a needle bar mounted in said bore for reciprocation therein and provided at its upper end with a Scotch yoke into which said eccentric pin extends, a vertically extending chamber in said face portion and parallel to said bore and needle bar, a member slidably mounted in said chamber and correlated in mass to said needle bar, and an operative connection between said bar and member and located in said face portion of the head and causing the reciprocating movement of the needle bar to impart out of phase reciprocation to said member and including rack teeth formed on the adjacent sides of said bar and member while said face portion is provided with interior openings communicating with said bore and chamber and exposing said rack teeth, while an idler gear is mounted in said face portion intermediate said bar and member and extends into said openings and constantly meshes with said rack teeth.

3. In a sewing machine head as dened in claim 2 and wherein said bore and said chamber are located in the vertical plane passing axially through said shaft.

4. In a sewing machine head as defined in claim 2 and wherein the wall of said chamber is provided with a longitudinally extending slot while said member has secured thereto a guiding element extending into said slot and maintaining said member against rotation in said chamber but allowing reciprocation thereof.

References Cited in the tile of this patent UNITED STATES PATENTS.

23,577 Hicks Apr. 12, 1859 1,142,082 Diehl et al. June 8, 1915 1,748,709 Gatchell Feb. 25, 1930 2,639,737 Forsberg May 26, 1953 

